Lubricating means for electric motor-clutch drives



Nov. 21, 1950 E. P. TURNER ET AL 2,531,175

LUBRICATING MEANS FOR ELECTRIC MOTOR CLUTCH DRIVES Filed June 10, 1948gnaw whoa) .Fdgar 1? Turner am WWWW Fran/e .AZ. Hayes 9&1? gg' gPatented Nov. 21, 1950 LUBRICATING MEANS FOR ELECTRIC MOTOR-CLUTCHDRIVES Edgar P. Turner, Fanwood, and Frank A. Hayes, Middletown, N. 3.,assignors to The Singer Manufacturing Company, Elizabeth, N. J., acorporation of New Jersey Application June 10, 1948, Serial No. 32,233

Claims.

as the shaft and bearings are enclosed to prevent lint, sizing and otherforeign material from finding their way into the motor bearings, themotor shaft and ball-bearings are completely enclosed. It is the objectof this invention to provide improved means for supplying lubricantthrough the rotary motor shaft to the enclosed ballbearings in which theshaft is journaled and to meter the lubricant so that it will besupplied equally to the two bearings. A further object of this inventionis to provide improved means for conducting lubricant from an externalfitting to '2 the bore in the shaft, which means becomes effective uponthe application of grease under pressure at the fitting.

The above being among the objects of the present invention, furtherobjects relating to details of construction will be apparent from thefollowing detailed description.

The accompanying drawing represents a vertical sectional view takenthrough the center of an electric transmitter embodying our invention.

In the embodiment of our invention selected for illustration, thetransmitter comprises a casing formed in two parts It] and H securedtogether in the usual manner by screws (not shown) to form a substantialcylindrical casing or frame. The part H) is formed with an inwardlyextending central tubular portion l2 on which is tightly fitted astationary electro-magnetic element i3 having the usual four pole, threephase winding 14. The rotary electromagnetic element is disposedexternally of the stationary element [3 and comprises a ring typesquirrel cage rotor [5 se cured to a die-cast spider it having a hub ll,splined to one end of a motor shaft 18 journaled in the spacedball-bearings l9 and 28 which are located interiorly of the tubularportion [2. The spider [6 has secured to it a driving friction disk 22which is held in position in a suitable depression in the face of thespider by a split ring 23. The external rotor together with the spiderare in effect a fly-wheel which acts as a driving element of the clutch.

J ournaled in the bearings 24 and 25 carried by a hub 26 of the framepart II is a shaft 21 which has secured to its inboard end the drivenelement of the clutch. The outboard end of the shaft 2? is splined toreceive a split hub 29 having a radially extending flange so to which issecured a pulley 3| adapted to drive a sewing machine. The shaft 2i isadapted to be moved endwise by a suitable mechanism so as to cause thedriven element 26 of the clutch to engage the driving element or thestationary brake 32. For a more complete and detailed description of theconstructive features of the transmitter, reference is made to theco-pending patent application of Edgar P. Turner, Serial No. 696,828,iiled September 1d, 1946, for Electric Transmitters.

nixed by screws 53 to the part lo 01' the frame is a bell shaped coverplate 33' which has secured to its central portion a tubular stud 34having a grease-gun hating screwed into its free end. elidably fittedinto the tubular stud 34 is a tube having a reduced or restricted axialopening 3? in its end nearest the grease fitting, and its other end istapered at 33 for entrance into a conical opening so formed axially inthe end of the shaft iii. The conical opening 40 merges into a centrallyarranged longitudinal conduit 4| which is connected to a radiallyarranged duct 42 formed in the shaft [8. The shaft i8 is also formedwith two shoulders 43, 44 and a diametrically reduced portion 45 betweensaid shoulders. Surrounding the reduced portion 45 of the motor shaftand extending a short distance over each of the shoulders 43, 44 is asleeve 45 which defines together with the reduced portion of the shaft,a lubricant passageway 4: which communicates with the radial duct 42.

From the foregoing it will be apparent that when grease is suppliedunder pressure by a grease-gun through the fitting 35 the pressure ofthe grease in the chamber 48 will cause the tube 36 to slide to theright, as viewed in the drawing, and its tapered end 38 will be forcedinto the conical opening 40 in the shaft 18. When this occurs, thegrease will flow through the restricted or reduced opening 31 of thetube 36, thence through the tube into the longitudinal bore 4|, throughthe radial duct 42 and into the space 4'! between the reduced shaftportion 45 and the sleeve 46. There is a slight clearance between theshoulders 43, 44 and the inner periphery of the sleeve 46 and,therefore, the grease under pressure will fan out radially of the shaftl8 and pass outwardly between the inner races of the ball-bearings andthe ends of the sleeve 45 and ooze into the ball-bearings l9 and 25. Itwill be observed that when the transmitter is operating, centrifugalforce will tend to throw the grease outwardly and into the bearings andthat grease will be supplied equally to each bearing. It will also beobserved that if too much lubricant is supplied to the bearings theexcess will accumulate in the chamber 48 between the outer periphery ofthe sleeve 48 and the inner surface of the tubular frame portion I2,thereby preventing the excess grease from finding its way into theinternal parts of the motor and its windings.

Having thus set forth the nature of the invention, what we claim hereinis.

1. In an electric transmitter having a casing formed with a centrallyarranged tubular portion carrying spaced ball-bearings, the combinationof a motor shaft journaled in said bearings and formed with an openingin one of its ends, a tubular stud having its axis alined with the axisof the motor shaft and spaced therefrom, a tube formed with a restrictedopening in one end and slidably mounted in said stud, means forsupplying grease under pressure to one end of said stud, and conduitsconnecting the opening in the end of the shaft with said spacedball-bearings.

2. In a motor-clutch driving device having a frame with a centrallyarranged tubular portion carrying spaced ball-bearings, the combinationof a shaft journaled in said bearings and formed with two shouldersarranged adjacent said bearings and providing a reduced portiontherebetween, a sleeve enclosing the reduced portion of said shaft andextending over said shoulders to form a lubricant passageway restrictedat each end, and means for forcing lubricant through said passageway andout through its restricted ends to the ball-bearings in which the shaftis journaled.

3. Means for supplying lubricant to the bearings of an electric motor ofthe external rotor type comprising a stud carried by the motor, a tubeslidably mounted in the stud and having a restricted opening in one end,a motor shaft formed with an opening and having its end 4 spaced fromand arranged coaxial with said stud, lubricant conduits connecting theopening in the shaft with the shaft bearings, and a grease fittingcarried by said stud whereby grease may be supplied to one end of saidstud under pressure.

4. Means for supplying lubricant to the spaced ball-bearings of anelectric motor of the external rotor type comprising a stud carried bythe motor, a motor shaft formed with lubricant conduits and axiallyspaced from said stud, a grease fitting carried by said stud, a tubeslidable in said stud for supplying grease from said fitting to theconduits in said motor shaft, said tube being effective when grease issupplied under pressure to said fitting, and means embracing said shaftfor causing the grease supplied to said conduits to be delivered to eachof said bearings.

5. A motor-clutch driving device having a frame including an internallyarranged tubular portion, ball-bearings seated in and spaced from eachother longitudinally of said tubular portion of the frame, a motor shaftjournaled in said ball-bearings and having a diametrically reducedportion terminating in shoulders disposed adjacent and between saidball-bearings, a sleeve surrounding and spaced from the reduced portionof said shaft and overlying said shoulders in slightly spaced relationthereto, said sleeve and said tubular portion of the frame definingtherebetween an excess lubricant storage chamber, and means including alubricant conduit in said shaft for supplying lubricant through thespace between said sleeve and the reduced portion of said shaft to saidball-bearings.

EDGAR P. TURNER. FRANK A. HAYES.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,038,293 Jacob Apr. 21, 19362,256,296 Smith Sept. 16, 194:1 2,282,589 Mayne May 12, 1942

